Are beetles beneficial insects or pests? Learn to tell them apart correctly

Beetles are a common type of insect when growing crops. Because they are diverse in species and form a large family, they eat different foods, so are beetles beneficial insects or pests?

1. Are beetles beneficial insects or pests?

Some beetles are beneficial insects, and some are pests. For example, some beetles in the families Coccinellidae (ladybugs), Carabidae (ground beetles), Cicindelidae (tiger beetles), and Meloidae (blister beetles) are beneficial insects. Mites, moths, maize weevils, mung bean weevils, pea weevils, locusts, cutworms, wireworms, ants, cockroaches, spiders, bedbugs, fleas, grain borers, and cotton bollworms are pests. Generally, most beetles are pests, and there are more than 200 species on corn alone and more than 400 species on apples.

2. Are beetles poisonous?

There are many kinds of beetles. Some are poisonous and some are not. For example, blister beetles and beetles in the family Carabidae are poisonous.

1. The most poisonous beetle is the blister beetle, also known as “blister fly”, “dragon beetle”, and “earth gall”. It belongs to the order Coleoptera, family Meloidae, genus Mylabris. The hydrogen cyanide released by one blister beetle can kill a cow. In addition to the hydrogen cyanide produced by the last abdominal segment, a yellow venom, cantharidin, is secreted from the leg joints. It can destroy the cell tissues of higher animals, and after contact with the human body, it can cause skin redness, swelling, and blistering.

2. Beetles in the family Carabidae spray a liquid with an extremely irritating odor to defend themselves. Although it is non-toxic, the smell is hard to describe. Some beetle larvae, such as firefly larvae, can release anesthetic, but it is not harmful to humans because the amount is too small.

3. Very few kinds of beetles are poisonous. Basically, all the ones you can see are non-toxic. Some ground beetles and lampyrid larvae (that is, firefly larvae) secrete some chemical substances that have a mild effect. There is also the blister beetle that Lu Xun once mentioned. Family Meloidae. This family also has some irritating substances, but they are not harmful and can instead be made into medicines.

Overall, some beetles are beneficial insects and some are pests. For example, ladybugs, tiger beetles, and dung beetles are beneficial insects, while longhorn beetles, weevils, plant bugs, and bedbugs are pests.